Looking back on a bit of history
Back at the foundation of NRA-ILA, the leadership thought the argument that there was a constitutional right to arms could not be a winner: yes, WE believe that, but no one else does. (Not a surprising view, if the only way to judge public opinion was through the mass media, and remember we're talking 1978).
They commissioned a polling firm, Decision Making Information, to do a survey and find out WERE winnable arguments. Most of the data obtained were not surprising revelations. People were concerned about crime, favored locking criminals up, etc.. Then it came to Table 12. "Do you believe the Constitution of the United States gives you the right to keep and bear arms"? Yes: 87%.
We're weren't just talking in an echo-chamber of true believers!
UPDATE: Ah, Jimmy Carter. I have in my files somewhere the result of a Freedom of Info Act request, made decades go, relating to communications leading up to the 1980 election. I remember a memo from one staffer saying, essentially, someone is going to have to tell the antigun groups that we aren't going to do anything for them, and this must come from someone above my pay grade. Then there was Ted Kennedy, who was challenging Carter in the primaries. Handgun Control, Inc., which later became Brady Campaign, was pushing him to introduce a gun bill, and finally came out with a press conference saying he was going to do it ... which he got around to a week or two later. I interpreted that as -- even Kennedy didn't want to go public with a gun control bill at that point in time, and their press conference was a surprise move to push him into it. That may have been the point when the gun rights movement turned the corner. It wouldn't win them all, but the battle had turned from a retreat into at least a stalemate.